There are numerous standards for encoding numeric and other information in visual form, such as the Universal Product Codes (UPC) and/or European Article Numbers (EAN). These numeric codes allow businesses to identify products and manufactures, maintain vast inventories, and manage a wide variety of objects under a similar system and many other functions. The UPC and/or EAN of the product is printed, labeled, etched, or otherwise attached to the product as a dataform.
Dataforms are any indicia that encode numeric and other information in visual form. For example, dataforms can be barcodes, two dimensional codes, marks on the object, labels, signatures, signs etc. Barcodes are comprised of a series of light and dark rectangular areas of different widths. The light and dark areas can be arranged to represent the numbers of a UPC. Additionally, dataforms are not limited to products. They can be used to identify important objects, places, etc. Dataforms can also be other objects such as a trademarked image, a person's face, etc.
Scanners that can read and process the dataforms have become common. Bar code scanners having generally gun shaped housings were originally introduced around the year 1980. At that time, laser scanning technology was used because only laser scanning could provide enough working range to make the aim-and-shoot ergonomics of a gun shaped housing meaningful. Around the same time, bar code scanners using linear CCD sensor arrays, or imaging scanners, were also introduced. The working range of the first imaging scanners were less than laser scanners. Thus, imaging scanner housings were designed to facilitate scanning by touching a wide mouth of the scanner to the barcode, as opposed to shooting at the barcode from a distance, as could be done with a laser scanner. Eventually, the working range of imaging scanners were expanded, and scanner developers began to design them with gun shaped housings, similar to what had become popular with laser scanners.
When scanning from a distance, an ergonomic scanner housing can be shaped like a gun. Several companies build and sell gun shaped, extended range, imaging scanners. The general construction of known imaging scanners comprise an optical assembly located in the head or gun barrel portion of the housing. This optical assembly includes a lens positioned towards the front of the housing, that focuses an image of the barcode onto the sensor array located towards the back of the housing. Two or more light emitting diodes (LEDs) are mounted near the back of the housing and are focused, with additional lenses, onto the barcode, to illuminate the barcode and to visually guide a user as to where the scanner is aimed. The sensor, the LEDs, and the lenses are mounted together in a molded plastic assembly that maintains their positions with respect to each other so that their desired functions can be performed.
Additionally, the image scanner comprises a circuit board carrying the various electronics that process and decode dataforms, control the sensor and the LEDs and perform other scanner functions. The senor and LEDs are electrically connected to the circuit board and the circuit board is conventionally mounted horizontally in the head of the scanner, just below the optical assembly.
A communication interface that enables the scanner to communicate with a host computer or a cash register is also located in the housing, and electrically coupled to the circuit board. For example, the communication interface can be implemented as a communication interface connector with interface circuitry. Some known scanners position the interface circuitry in the head of the scanner housing on the same circuit board as the other electronics, while others position the interface circuitry on a second circuit board located in the housing's handle.
When determining the relative position of the sensor, the LEDs and the circuit board, in known scanners, the needs of the optical system are considered before the ease of making their electrical connections. Therefore, to make the electrical connections between the sensor, the LEDs and the circuit board, a flexible circuit assembly, or flex circuit, having a complex shape is shaped and folded around the optical assembly to allow soldering. Flex circuits are also used to electrically connect to indicator LEDs that are visible through transparent areas in the top of the housing and to audio indicators, or beepers, which audibly indicate when the scanner has decoded a barcode. The circuit board can also comprise connectors that are soldered to the board, which allow flex circuits to connected to the circuit board by inserting the flex circuit into the connector. The connector allows the circuit board to be electrically connected as necessary, via the flex circuit, to the electronic components mounted in the optical assembly.
The disadvantage of the known system described above is the cost of the flex circuits and connectors, sometimes costing a significant percentage of the entire material cost of the scanner. In addition, the flex circuit can disengage from their connection to the circuit board if the scanner is dropped on the floor, causing the scanner to fail. Another disadvantage is that the sensor, LEDs and beeper must be hand soldered to the flex circuit, requiring skillful and highly paid manufacturing people.
Gun-shaped scanners generally communicate with a host computer or cash register via a cable coupled to a communication interface connector located at the bottom of the handle of the scanner. This communication interface connector must be electrically connected to the rest of the scanner's circuitry, which is, as described above, at least partially mounted on a circuit board in the scanners head. Several strategies have been employed to make this electrical connection. Some scanners comprise an additional flex circuit connecting the main circuit board, in the head of the scanner, to the communication interface connector in the bottom of the handle. The communication interface connector has to be mechanical secured to the bottom of the handle to hold the interface connector in its desired position. The mechanical connection generally consists of a molded plastic part held in place with a screw. The extra components, and the labor needed to install them further increase the cost of the scanner. In addition, scanner reliability is further reduce because there are more flex circuits that can become disconnected from the circuit board if the scanner is dropped or subject to vibration.
Another way to electrically couple the communication interface connector to the bottom of the handle is to mount a second circuit board in the handle, with the interface connector soldered directly to the bottom end of the second board. A small ribbon cable or flex circuit is still needed to couple the second circuit board to the main circuit board located in the head of the scanner. The ribbon or flex circuit is normally coupled the circuit board through connectors located on the board. This assembly is expensive and can be unreliable because the ribbon or flex circuit can become disconnected from its connectors at either board. The secondary circuit board is held in place using a screw and retaining bracket, adding additional cost.
Laser scanners having a single vertically oriented circuit board have been constructed, but the practicalities of building an imaging scanner with a similar construction are different. Some known laser scanners include tilted sensors, but since image quality is so important in imaging scanners, known imaging scanners do not include tilted sensors.
Accordingly, there is a need for an imaging scanner that can lower the cost of the scanner and increase reliability by eliminating flex circuits, reducing the amount of soldering and reducing the number of circuit board connectors.